Electrical devices



July 12, 1960 LUDWIG ELECTRICAL DEVICES Filed June l5, 1959 INVENTOR. ou/5 aow/6 (al, 424A q rro Y6 MM A' j.,

Afa

elements.

United States Patent O,

`Mfg. Co., Inc., 23--10 Bridge Plaza S., Long Island City 1, NY.)

Filed June 15, 1959, Ser. No. 820,169 2 Claims. (Cl. 200-51) This invention relates to electrical devices.

. It is an object of my invention to provide an electrical device having a novel means for rapidly securing plural parts of aV casing to one another in a simple manner which lends itself to high speed automated assembly.

It is another object of my invention to provide an electrical device wherein the securing means, when once operative,`absolutely prevents any subsequent shifting of the casing parts with respect to one another or the contact It is another object of my invention to provide an "g electrical device wherein a connecting means is included which is so arranged that the parts of the casing cooperate with one another to permanently lock themselve together. Y p lt is another object of my invention to provide an electrical device whereinthe connecting means constitutes an extremely simple, single inexpensive part that is foolproof and rugged in operation.

It is another object of my invention to provide a combined switch and contact element which cooperate in a unique and Ahighly desirable manner that assures positive, eilcient and reliable operation.

Other objects of my invention in part will be obvious and in part will be pointed out hereinafter.

My `invention accordingly consists in the features of construction, combinations of elements and arrangements of parts which will be exemplified in the device hereinafter illustrated and described and of which the scope of application will be indicated in the appended claims.

ln the accompanying drawings in which is shown one of the various possible embodiments of my invention,

Fig. 1 is a central sectional view through a night light incorporating my invention, the same being taken substantially along the line 1--1 of Fig. 2; l

Fig. 2 is a sectional view taken substantially along the line 2-2 of Fig. l; and

Fig. 3 is a perspective view of the unitary combined connecting and contact element utilized in accordance Vwith my invention.

Referring now in detail to the drawings, the reference numeral denotes a night light which incorporates the basic vprinciple of the present invention and typies an electric device which embodies all the features thereof.

The night light 10 includes a casing which, pursuant to the instant invention, is formed of two sections 12, 14. As illustrated, the two sections are not mirror images of one another and in general the particular contour of the individual sections of the casing is of no importance except that they must mate to define a casing; that is to say, they must, when brought into abutment, cooperate to provide a housing. For this purpose, the two sections are hollow with an open side, i.e. depressed, the two open sides being adapted to be brought together to form afhollow housing. Pursuant to standard practice, the two individual sections are made fromv an electrically non,- conductive` material which is unaffected by elevated temperatures, eg., temperatures up to 300 F., typical mate- ,A 2,945,098 YPatented July 12, 1960 iCC 2 rials being hard rubber, or, preferably, a thermosetting plastic as, for example, a phenol formaldehyde condensation resin.

The specific exterior and interior configurations of the two sections and of the resulting casing will depend upon the functional use of the electrical device, and, as an example, the specific shape of the night light 10 will be described in detail hereinafter. However, pursuant to the principal aspect of the instant invention, the internal congurations of said sections include at least one pair, and desirably at least two pairs, of associated, preferably registered, bores, i.e., wells. That is to say, at least one well, and preferably two wells are provided in one section, and at least one well, and preferably two wells are pro# vided in the other section, the wells of each pair (one well in each section) preferably being in linear registration. Moreover, the wells in each section have one open end facing toward the other section, the lengths of the wells in both sections preferably being perpendicular to the abutment plane between the two sections. 'I'he wells may be blind or may have both ends open as soon will be appreciated.

Specifically, the casing half 12 includes the blind wells 16, 18 which are molded into the interior thereof. Each said well is of uniform, transversely elongated crosssection except near its blind end where it is of reduced size. The wells 16, 18 are mirror images of one another in that the aforesaid reduction in cross-section is oppositely arranged as can best be seen in Fig. 2. The cross-sectional contour of the Wells is approximately oblong with two corners of one long side blocked olf. A well 16, 18 alternatively might be described as constituting a first portion which is of uniform oblong crosssection from the open end to the blind end and a second contiguous rsmaller portion which is of uniform crosssection and extends from the open end almost all the way to the blind end, terminating at a shoulder 2G. The second` portion is narrower than the lirst portion and is arranged symmetrically with respect to the longitudinal axis of the first portion.

The other casing section 14, likewise is provided with two wells, these being denoted by the reference numerals 22, 24. The latter wells have both ends open, unlike the blind wells 16, 13. Moreover, the latter wells are of uniform cross-section from end to end. The outer ends of the wells 22, 24 are on the outside of the casing for the night light. The inner ends of the Wells 22, 24 terminate within the hollow interior of the casing. It will be observed that the two halves abut one another at a plane zone 26. 'Ihe longitudinal axes of all the wells 16, 1S, 22, 24 are perpendicular to this plane zone. Moreover, each well of each casing section is in registry with its associated well in the other casing section, i.e., the well 16 is in registry with the well 22 andthe well 18 is in registry with the Well 24 when the casing sections are properly assembled. The night light further includes unitary contact and connecting elements; that is to say elements which in the preferred form of my invention perform dual functions. Considered from the point of View of novelty, the primary function of the two elements is to connect the two halves of the casing and their secondary function is to act as electrical contacts.

Considered operationally, each of the aforesaid elements includes two uni-directional locking members. That is to say, two members each of whichrcan move in one direction relative to third or fourth members but which will automatically lock against relative movement in an opposite direction. The uni-directional movements of the two members of each element are oppositely acting, i.e. one member can move relative to a third member in one direction but will lock against relative movemove relative 'to a fourth member in said other direction' but will lock against relative'movement in said one direction. Moreover, each element includes structural means` per-iinV entry. interconnecting tnenrst `'two rnenrb'ersinsnen a 'illf that peiJSbl IOV'eUe'IIZ 0f the hf fourth members relative to the lirst two members is toe' ward Ythe area between 'said rirst two members, while the thirdand -fo'urth members are locked against relative movement outwardly away from the area between the rs't two-members.

More specilically each unitary contact and connecting element is indicated by therefe'rencenumeral 28. Since the 4elements are alike, only one will be' described. lt is "falso worthwhile to note that, although I 'have shown and now will describe male vcontact elements, {my invention is equally applicable to contact elements of the female type. Said contact element 28 is fabricated from any of the usual materials, eg. vresilient electrically vcondct'ive strips'tock, vsuch for instance as resilient brass or phosphor bronze. Great resilience is not required; in de'ed the normal resilience of ordinary brass rather stii sheet stoel; will serve my purpose. The element 28 has a straight flat body 30, connected at the male prong end thereof by an abrupt retroverted bend 32 to a return leg' 34 which lies ilat against the body and extends back about half 'the length of 'the body to form the male prong. The provision ofsuch 'a body and leg is entirely conventional in the electric iixture lield. Als'o conventional is the presence of theV registered pair of openings 36 near the P 0f '1-l5f'f. 1gl l The principal novelty of my invention lies in the provision on said contact element of the two uni-directional "ananas .i

the well and prevent such movement. Using the earlier "terms "of reference, the tang 38 yconstitutes one uni-directional locking member which can experience free movement into the well, but automatically locks -to prevent reverse movement; or considered from an opposite point of view, the casing can move to receive the tang 38 and body 30 but cannot thereafter. Bemoved away therefrom.

The second uni-directional locking member constitutes a pair of corner t'an'gs 40 formed' by 'bending out the tree comersof the leg 314.`v These corners are bont tQ be angulrly inclined to .thenpla'ue of the legA 34 andxtherefore of the body 30. The direction of orientation is such the corners are inclined toward the tang 38. The distance that the' tips ofthe 'tangs '40 peipendi'cularly project from the leg .34 and body 30 isjsuch that, when the male prong is introduced in either well 22, 24 with the bend 32 foremost, there is insunicient space to accomvmodate the tangs so .that as the tangs 40 enter` one of thelwells 22, 24 they will be bent and their tips will drag locking members to which reference was made above. i

'Ille lfirst of these members comprises a tang 38l carried by the body at'the end remote from the bend 32. The tang is formed from, e.g. struck from, the material of the body, thereby consisting of a tab, the tip and sides of which are -free of the body, and the base of which is in one piece with the body. The tang protrudes from the body in roughly a longitudinal direction. More partienlarly, Vthe tang isinclined in order to achieve my invention, the inclination being toward the opposite end of the body,V that is to say, -Where the bend 32 is located. The angle of inclination between the tang and the body is not critical, providing that it is less than 90 degrees.

It is to be observed that the width of the body 30 is interrelated with the width of the first portion of the wells 16,18, the dimensions of these two components being such that the body is a vfree-sliding lit in said lirst portion. The tang .is dimensionally interrlated with the Second portion of each 'of the Wells 16, 18, the width of the tang being just slightly less than the width of said second portion so that considered only widthwise each tang has a free-sliding lit the associated second portion of the well. i

However, the perpendicular distance the tang protrudes from the body does not fmatch in the foregoing fashion the corresponding dimension of the associated well, in that thetang projects (when unstressed) from the body a distance greater than the corresponding dimension of the second portion of the associated well. Accordingly, when during assembly of a night light the body of 'the element 30 is thrust into a well A16, 18, the tang will not be freely received in said well, but will be exed toward the body as it enters the well, the flexing being away from the direction of movement of the body, and will drag. against the associated side of theweil as itis pushed deeper into the well. Due to the inclination of the tang in a direction having a component opposite to Vthe dire'ctitnrof bodily movement experienced by the tangnponentering thewell, the tang can be forced into the well. However, whenl it is attempted to move the body v3i) in the 4opposite (retrograde or outward) direction with respect to the well, the tip of the tang will biteinto against the associated wall of the well, permitting the tangs to inove in that direction. But as soon as it is attempted towithdraw ythe contact element 28 the tips ofthe tangswill bite into and vengage 'said Wall of the well to prevent such nrt'etrogijade movement.

rtjwili be observed that the tangs y40 are inclined oppositely toV 'the 4ta'rigftt v'so that th'e vdirection of free movement 'o lthe 'wells 'in' the ltwo casing sections with respect to all of said tangs is inwardly toward one another, and the in ifvhich' the vWells are locked against 'movement outwardly apart from one another. It should be inentionedth'at the described tlexions 'of the tang'38 and the tangs 40 inay be very slight, indeed unnoticeable to the human eye. Only a tiny amount of bending `is re@ quired restore up en'ughje'nergy to cause the tangs to bear against the associated/'walls 'of the v'velll `so as -to bite ito and brake against thorn when it is attempted to move the wells outwardly away from one another.

It will be sen'th'at a'sis indicated, the element 28 iseonpled to 'thefeasin'g half 14 by introduction of the bend 32 into a well freni` the inside of said half, said bend will protrude from the casing half when the tangs 40 are disposed in the well whereby the exposed tip and following part of the element'ZS may function as male contact element. `Italso will be obvious that the element 2.8 will work 'equally well a's' a unitary coupling and contact element it were shaped as a conventional yfemale con# tact provided', of course, that it included oppositely inclined tangs leaning ltoward one another and adapted to engage opposed easing sections.

- To assemble the 'casing for thenight light 10, the interror ends of the t`v'vo contact elements 28 bearing the tangs 38 'are introduced into the wells 16, 18 far enough for the ktangs 38 to bear against the 'second portions of said wells. The male prongs of the elements are introduced into the wells 22, 2 5 `far 'enough for the tangsv 40 'tojbea against lthe associated walls of said wells. -At this time, the two halves of the casing still may be spacedv apart.Y Now the two halves are brought into contact at the plane z'o'rle 2 6. ln so doing, one of both of 'the sections 12, 1-4 'will' moverlatiye' to the elements 28. This operation preferably is performed with the aid of 'a jig, or automatically, so that the distances vthe two r'ri'l'e' prongs of thef'c'ontact elementsprojeot from the casing half'l will lbe 'controlled to a common desired predetermined length, -In the preferred form of my invention, the interior ends of the elements 2s will, at this titne,'bje adjacent the blind ends of the wells 16, 18.

It will be appreciated from a study of the foregoing construction that when the two halves of the casing are abutted against one another, the contact elements are Alocked against relative movement, longitudinal movement 4in one direction being' barred bythe tang 38 and inthe opposite' direction by the tangs 40; Neither casing half is able .to move relai-ivato the eontaet elements. For

gradely with respect to the contact elements because of the tangs 38. lt is unable to move further onto the contacts 2S because Ito do so would require retrograde movement of the casing half 14 which movement is barred by the tangs 4i). The same considerations prevent movement of the casing half 14 with respect to the contacts. Thereby, with an extremely simple construction, vnot requiring threading, auxiliary connectors or riveting, I have arranged to secure two casing halves to one another permanently with a mere thrusting action. By utilizing the contacts to couple the casing sections l am, moreover, able to eliminate an extra operation 'and an extra part.

Although the casing coupling arrangement above described is designed to be employed in an electrical device having contacts, and although such arrangement even is capable of use where the coupling elements do not funcvtion as contacts, I have shown said combined coupling and contact elements herein in connection with `a specific electric device, to Wit, a particular night light in which the elements assume a third function which will become apparent as this description proceeds.

To utilize the casing for a night light, I provide in each casing half 12, 14 a branch 42. The twol branches cooperate to form an internally threaded husk, as is conventional, which is adapted to `receive the threaded ferrule on the stem of a small standard electrick light bulb (not shown). I also include in the night light the usual side and center contact strips 44, `46 which respectively are adapted to engage the ferrule and center tip of said stem.

The center contact strip 46 has an intermediate portion 4S which is snugly received in a channel S0 formed in a partition Wall 52 in each of the casing sections 12, 14. The center strip y46 also has a portion 52 which lies athwart one of the contacts 28 (the left-hand contact as viewed in Fig. 2), being held in position against the contact by engagement with la sloped side wall 54 in each of two channels 56 formed in transverse partitions 58, 60 in each of the two casing sections. The strip 46 can simply be placed in the channels 48, 56 prior to assembly and it will be clamped in place upon the juxtaposition ofthe casing sections.

The side contact strip 44 has an intermediate portion 62 which is received in a channel `64 in the partition wall 52 of each of the two casing sections. AThe interior end 66 of the strip 44, i.e. the end remote from the husk, is so shaped that when in idle position it is remote from the other contact 28 (the right-hand contact as viewed in Fig. 2), said end 66located in a chamber 68 provided in the hollow interior of the casing sothat it can be tiexed into engagement with and away from said other contact 28. It will be quite apparent that when the end 66 is spaced from the contact 28 the light bulb in the husk will be deenergized, and when the end 66 touches the contact the bulb will be energized.

Suitable means is included to ex said end 66 in the manner just described. Said means conveniently may be of the type illustrated in my U.S. Letters Patent No. 2,743,330, for Silent Switch Structure, issued April 24, 1956. More particularly, I form a bore 70 in the casing section 14 between and parallel to the wells 22, 24, said bore having a closed bottom end and opening into the interior of the casing. A helical compression spring 72 has one end seated against the closed end of the bore and a ball 74 rests atopv the other end of the spring. The bore is of sufciently large diameter to permit the spring and the ball to sway therein and, as shown in Fig. l, at least the upper end of the bore where the ball 74 is disposed is elongated transversely to the side contact strip 44 so 'as to allow fthe ball to be shifted in a direction perpendicular to said strip.

The switch structure further includes a shaft 76 perpendicular to the path of travel of the hall, said shaft being carried in the upper casing section 12. Pivoted on the shaft '76 is a lever 7S adapted to be operated. by hand and having a nose 80 which bears against the ball. By oscillating the lever, the nose may be arranged to bear at will against either side of the ball. When the nose bears against the side shown in Fig. 2, it forces the ball away from the end 66 of the strip 44 which thereupon assumes its idle position in which it is spaced from the contact 28. If now the lever 'i8 is rocked toits either extreme position to bear against the oppositeside of the ball 74, said ball will force the end 66 of the side contact strip against the contact 28 to close the energizing circuit for the bulb.

It now will be appreciatedv that the third function of the contact is as the stationary element of a switch.

It will be appreciated that by virtue of the foregoing construction I have provided an electrical device which is able, with very few parts, to provide contacts for circuits and electrical parts permanently interconnecting several casing parts and perform the functions of a simple switch.

It thus will be seen that I have provided an electrical device which achieves the several objects of my inven-V tion and is well adapted to meet the conditions of practical use.

As various possible embodiments of my invention might be made and as various changes might be made in the embodiment above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. An electrical device comprising a hollow casing, including two sections abutted against one another and having wells, said wells facing the zone of abutment, at least one electrical contact having at least a portion thereof located within said casing and including resilient protuberances inclined toward one another and integral with said contact, one of said protuberances being uni-directionally frictionally received in the well of one section and the other protuberance being uni-directionally frictionally received in the well of the other section, whereby said protuberances lockingly engage both said sections and retain them in abutment with one another.

2. An electrical device comprising a hollow casing including two sections abutted against one another and having wells, said wells facing the zone of abutment, at least one electrical contact having at least a portion thereof located within said casing and including resilient tangs inclined toward one another and integral with said contact, one said tang being uni-directionally frictionally received in the well of one section and the other tang being uni-directionally frictionally received in the well of the other section, whereby said tangs lockingly engage both said sections and retain them in abutment with one another. Y

References Cited in the le of this patent UNITED STATES PATENTS 2,595,799 Ludwig VMay 6, 1,952 

